by Kimberly Allen, RN
A few weeks ago a young couple I know took their infant son to the emergency room with severe difficulty swallowing, eating and breathing. He was admitted to a pediatric intensive care unit for evaluation and treatment. At first the Drs thought he had been exposed to some type toxin and the began to run tests to determine the problem. A few days later the Drs went to the parents with their results. It was devastating news for the family. Their infant son had spinal muscle atrophy.
Spinal muscle atrophy or SMA is an autosomal recessive disorder, which means you have to inherit a defective gene from both parents. However, SMA has been known to develop without hereditary causes in approximately 2-4% of the total cases.. SMA affects people of all races at a rate of 1 in every 10,000 people with approximately 1 in every 50 people being carriers.
There are four types of SMA each with it’s own age of onset and symptoms.
Type I is also called infantile with an age of onset from birth to 6months of age. This is usually the most severe type. There is usually a sudden and rapid onset of symptoms. Usually a condition called “floppy baby syndrome” develops first, followed by the rapid death of motor neurons. The death of the motor neurons causes problems in the major body systems, especially the respiratory system. Respiratory failure is the leading cause of death in infants with this type. Infants diagnosed with this type of SMA rarely survive past 2 years of age.
Type II or intermediate, also called Dubowitz disease is usually diagnosed between 6-18 months of age. Children diagnosed with this type demonstrate muscle weakness which can progress at varying degrees. Most children with this type will not be able to stand, however, they are eventually able to sit and maintain a sitting position. However, the respiratory system remains a major concern. The life expectancy of these children are slightly reduced, but with proper management most survive well into adulthood.
Type III or juvenile, also called Kugelburg – Welander disease usually begins to manifest after your child is 18 months old. Children with this type are eventually able to walk without any support, however, most tend to lose this ability as they get older. There is less respiratory involvement improving life expectancy to with in normal range.
Type IV or adult onset has also been classified as late onset type III. This type tends to manifest after you reach 30 years of age. It begins with gradual muscle weakness in your arms and legs. People with this type will require a wheel chair. However, they rarely have other complications and it doesn’t affect their life expectancy.
A there is no cure currently available for SMA treatment focuses of managing symptoms and providing supportive care. By supportive care I mean doing things like breathing exercises to help maintain optimal respiratory function and reduce the risk of infection. Or for babies and young children that are having difficulty swallowing a feeding tube may need to be placed in their stomach. Physiotherapy focuses on problems affecting not only the muscles and bones but the heart, lungs and circulatory system as well. Some children may need spinal support using a back brace or if needed surgery. And two areas that should not be forgotten are diet and exercise. It’s crucial that your child eat a well balanced diet. A nutritionist can help you with the types of food your child should eat. Exercise is vital to maintaining optimal circulatory function, improving range of motion and flexibility as well as preventing joint stiffness.
Though there is currently no cure for SMA there are several clinical trials in progress and research is ongoing.
Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to HealthAndFitnessTalk.com, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at firstname.lastname@example.org.